The present invention relates generally to an optical mask adapted to shine a sustained bright light into the wearer's eyes at selected times to modify circadian rhythms.
It has long been known that biological processes in most, if not all organisms vary rhythmically over time, and that the timing of these rhythms can be affected by exposure to light. Recent research suggests that the light must be very bright if it is to effectively modify biological rhythms in humans. Using carefully timed exposure to bright light, scientists have been able to change people's cycles of sleep and wakefulness, body temperature and hormonal secretion. Additionally, bright lights have been found useful in treating certain psychiatric disorders such as seasonal affective disorder and depression. It has also been suggested that light treatment may be useful to fight various sleep/wake problems such as jet lag and tiredness associated with shift work, and to improve nighttime vigilance and performance.
Bright lighting systems for modifying biological rhythms have traditionally consisted of large, bulky banks of fluorescent tubes or specialized bulbs. Such systems have several inherent drawbacks, including high energy consumption, high heat production and limited transportability. These restrict their usefulness outside of the laboratory environment, especially for mobile applications such as the treatment of jet lag.
Furthermore, some research has suggested that the critical time for bright light exposure for many therapeutic purposes is either late at night or early in the morning, when subjects are ordinarily asleep. Another advantage of bright light treatment during sleep time is that it does not take time away from preferred wakeful activities. With traditional lighting systems, subjects must be awake to receive treatment, for if they fall asleep they may shield their eyes or look away from the light source and thus receive insufficient exposure.
Therefore there is a need for a bright light source that is lightweight and transportable; develops sufficient light intensity to produce the desired biological effects; and reliably directs light into the user's eyes regardless of body position during sleep. Additionally, there is a need for a bright light source which may be turned on and off at preselected times during the day or night and is capable of turning on gradually so as not to disturb a wearer.